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Chris727

728 belt problem

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Chris727
Hi. I have been working on a 728 Broadmoor which throws the belt to drive the mower when you try to engage it. There is too much slack in the belt when it is disengaged, so much to the point the belt will almost fall off on its own. I have the correct Simplicity belt installed and all pulleys are free and in good condition. The belt guides and tensioners are also correctly adjusted as in the manual.


It wants to slip off the right pulley first, then the engine pulley.


I believe the problem is that the mule pulleys are moving back too far when disengaged and that there needs to be a stop of some sort to prevent it from doing so. There is some sort of stop (circled in pic) on the inside of the left pulley but it is too short to do anything.


If I have to I will make a stop of some kind but it just seems to me like I am overlooking something. Any ideas? Thank You in advance. Chris

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mowerman1193
I don't see any belt guides on the mule drive..I don't have a small frame at the time so I can't show you a picture but there should be some belt guides mounted to the bolt that holds the pully on..Also might be missing the belt guides that are supposed to be mounted to the tractors frame to keep the belt from coming off the engine pully...Maybe look in a manual for a description

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PatrickE
My 2 Broadmoors have the beltguide #34, up under the frame, half way between the mule drive and the engine pulley. Its sometimes tough to put the belt thru there, so it definitly holds the belt in place when disengaging or engaging. The bracket #17, activates the PTO safety switch on my 738. Pat

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mowerman1193
Ok the other picture is what my 728 had..I was thinking of my 717 with the 2 guides mounted on the pulley bolt..After seeing the second picture I remember the 728 had that number 34 part on it..

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Chris727
I did a little research and looked at a couple salvage broadmoors. My 728 is a # 990577 in which the part #17 in UCD's 1st pic is actually a plain flat piece from factory. I fail to see what this part accomplishes as it is too short to cause frame contact and it doesn't prevent the belt from coming off. There are a couple mfr #'s for the 728 and the newer one has the one he has pictured with a tab on the top to prevent slippage, or maybe as Patrick mentioned, to activate a safety switch. I found an old 6hp broadmoor which has the same flat stop, which my manual refers to as a "pulley stop" rather than a belt stop. I do have the large belt guide under the tractor frame, # 34 in the last pic. The odd thing to me is that my AC Homesteader 8 (earlier version) only had guards under the frame and according the the AC parts manual never had a pulley stop of any kind on the mule drive. I used it to cut grass for several years with no problems at all. At this point I am going to straighten the bumper and check the bushings on the pivot point of the mule drive and see if that makes any difference. Thank You. Chris

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UCD
The first picture/diagram I posted is from the 728 manual, the second picture/diagram is from the 738 manual. But I guess as usual my simplicity manuals are wrong and Greg's are right.

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Bunky
Here's Something Is the Belt too tight or Loose when engaged?? I see from the picture this Tractor doesn't have the original Briggs engine and maybe someone has changed the pulleys on the engine from original?? JMO

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Chris727
Bunky, good observation, I just put the tecumseh on this tractor and was able to re-use the original pulleys from the briggs. Belt is plenty tight when engaged. If I start the tractor with the deck already on, I can go and mow without problems.

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mowerman1193
Well after looking in the Broadmoor pdf manual I see a picture of the belt stop I am talking about..I still think all my Broadmoors I had (717,728 and 5010) had this belt stop..I don't have any Broadmoors anymore so I can't say for sure..I don't know how you guy post the pdf page in here but go here: http://www.simplicitytechpubs.com/6767PRINT/PDF_files/TP_400_0870_00_BM_S.pdf and go to page 44 in the pdf (bottom of manual page shows 42) Part number 21 belt stop..I think all my tractors had this part on both pulleys..(one on each side)..may not have been factory like that but it sure looked like it to me..

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msiebern
My 728 also has the second style belt stop. Got curious and checked the empart schematic to see what it had to say.


Maybe another case of the later models changed before the Simplicity parts manual was updated? Not shown in the picture, but mine also has a second set of the wire belt stops for the pto near the engine pully, like the ones on the drive belt. Not sure if they are original or if someone added them due to this problem. Following up, I checked my downloaded Simplicity file and found both shown, depending upon mfg. #.




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gregc
quote:
Originally posted by UCD
The first picture/diagram I posted is from the 728 manual, the second picture/diagram is from the 738 manual. But I guess as usual my simplicity manuals are wrong and Greg's are right.
Where did I say that anything you posted was wrong? I merely pointed out that belt stop #34 (the large wire belt stop) was used on the Broadmoor 727 thru the 5010. Here's links to some of the manuals for the 728 tractors that show that belt stop: http://www.simplicitytechpubs.com/6767PRINT/PDF_files/TP_400_1658_00_BM_S.pdf http://www.simplicitytechpubs.com/6767PRINT/PDF_files/TP_400_1616_00_BM_S.pdf http://www.simplicitytechpubs.com/6767PRINT/PDF_files/TP_100_3684_00_BM_S.pdf http://www.simplicitytechpubs.com/6767PRINT/PDF_files/TP_400_0870_00_BM_S.pdf Can you show me a link to a parts manual for a 728 Broadmoor that doesn't show that large wire belt stop or not?

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Chris727
Update: I removed the entire mule drive "clevis assembly" and found it is severely twisted. This could be why the pulley stop doesn't do anything. I will straighten it or find another one and see if this fixes it. Thanks for all the info. Chris

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UCD
N.O.S Simplicity Broadmoor PTO Pulley Bracket 165046 http://cgi.ebay.com/N-O-S-Simplicity-Broadmoor-PTO-Pulley-Bracket-165046_W0QQitemZ130141662088QQihZ003QQcategoryZ82242QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
[img]http://i23.ebayimg.com/04/i/000/ae/7f/79a6_1.JPG[/img]

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Chris727
Wow, brand new. My old one seems to have straightened out OK but may not hurt to get a spare. I'm out of town tommorow but on Friday will see if straightening it fixes the problem. Thanks for all the help! Chris

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Chris727
Problem is now solved. After straightening out the mule drive, the belts work properly, amazing what a difference a little bend can do to how something works. Thank You. Chris

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